package str;

import java.util.Stack;

/**
 * @author:WIN10
 * @date:2022/1/18
 * @describe:
 */
public class StringConcat {

    public static void main(String[] args) {
        StringBuilder _builder = new StringBuilder();
        _builder.append("lei");
        _builder.append("xyz");
        System.out.println(_builder);

        String email = "home@163.com";
        System.out.println(email.indexOf("163"));

        int i = email.indexOf(".");
        int i1 = email.indexOf("@");
        System.out.println("--->>" + i);
        System.out.println("--->>" + i1);

        if (email.indexOf(".") > email.indexOf("@") && email.indexOf("@") > 0) {
            System.out.println("是邮箱号码");
        } else {
            System.out.println("不是邮箱号码");
        }

        Stack stack = new Stack();
        stack.push(""   );
    }
}
